| A | B |
|---|
| deformation | all changes in the original location, orientation, shape, or size of a crustal rock body |
| stress | force applied to a given area |
| differential stress | stress on an object that is unequal in different directions |
| compressional stress | shortens and thickens crust |
| tensional stress | thins and stretches crust |
| shear stress | slippage of one rock mass past another |
| strain | actual change in shape or size of a rock body due to stress |
| elastic deformation | rock returns to original size and shape when stress removed |
| ductile deformation | rock ddep in the ground flows/folds in response to stress |
| brittle deformation | rock body near the surface fractures/faults in response to stress |
| field work | most common and useful technique for geological mapping |
| geological map | maps that describe and interpret rock structures |
| strike | compass direction of the line produced by the intersection of the rock layer/fault with a horizontal plane |
| dip | angle of the surface of a rock layer/fault to the ground |
| fold | series of wave-like undulations formed by compressional stresses |
| anticline | formed by upfolding (arching) of rock layers |
| syncline | formed by downfolds, or rock troughs |
| monocline | large, step-like folds in otherwise horizontal strata formed by faults that do not reach the surface |
| dome | large, roughly circular structure formed much like an anticline |
| basin | large, roughly circular sunken area |
| fault | break in rock that causes an offset |
| footwall | rock mass below the fault |
| hanging wall | rock mass above the fault |
| normal fault | hanging wall moves down relative to the footwall in response to tensional stress |
| horst & graben | another name for fault block mountains |
| reverse fault | hanging wall moves up relative to the footwall in response to compressional stress |
| thrust fault | a reverse fault with a dip angle of less than 45 degrees |
| strike-slip fault | large faults with small displacement that is a horizontal offset; transform fault |
| isostasy | vertical movement of earth's plates based on gravitational balance of land mass vs. asthenosphere depression |
| joint | vertical fracture in a rock body with no offset |
| plateau | broad arera of relatively high elevation |
| terrane | crustal fragment with a distinctly different geological history than its adjoining crust; think India |
| fault block mountains | formed by normal faulting; form parallel rows w/ pointed peaks |
| folded mountains | formed by reverse faults; randomly distributed w/ rounded peaks |
| thrust fault mountains | formed by thrust faulting; form tilted mountains that appear to overlap each other |
